Plasmon tomography

Abstract

Plasmon energy is produced by exciting a plasmon resonance at least one excitation position on a first surface of a first material, and the plasmon energy is detected at at least one measurement position on the first surface after the plasmon energy has propagated from the at least one excitation position to the at least one measurement position. An attenuation of plasmon energy is determined along a plurality of paths between the at least one excitation position and the at least one measurement position, and relative distances between the first surface and a second surface of a second material are determined at a plurality of points on at least one of the surfaces based on the determined attenuation of plasmon energy along the plurality of paths.

1. A system comprising:
 positioning structures configured to align a first surface and a second surface; 
 a source configured to excite plasmon energy at at least one excitation position on the first surface; 
 a detector assembly configured to produce signals corresponding to received plasmon energy at a plurality of measurement positions on the first surface spatially separated from the at least one excitation position by respective plasmon paths, wherein the plurality of measurement positions correspond to a fixed relative position of the first and second surfaces; and 
 a processor responsive to the produced signals to determine at least one separation distance between the first and second surfaces. 
 
     
     
       2. The system of  claim 1  wherein the processor is further responsive to the produced signals to create a topographical map of the second surface. 
     
     
       3. The system of  claim 1  wherein the source includes a laser. 
     
     
       4. The system of  claim 1  further comprising:
 a waveguide configured to direct energy from the source to the at least one excitation position. 
 
     
     
       5. The system of  claim 1  further comprising:
 a waveguide configured to direct energy from at least one of the plurality of measurement positions to the detector assembly. 
 
     
     
       6. The system of  claim 1  further comprising:
 one or more microelectromechanical structures positioned substantially between the first and second surfaces, the one or more microelectromechanical structures being responsive to signals to adjust at least one of the first and second surfaces. 
 
     
     
       7. The system of  claim 6  further comprising:
 a control system operably connected to provide the signals to the one or more microelectromechanical structures. 
 
     
     
       8. The system of  claim 1  wherein the processor is further responsive to signals to create an image of one or more objects located substantially between the first and second surfaces. 
     
     
       9. The system of  claim 1  further comprising:
 a control system operably connected to the source configured to excite plasmon energy. 
 
     
     
       10. The system of  claim 9  further comprising:
 a touch pad receptive of user input and operably connected to the control system. 
 
     
     
       11. The system of  claim 1  further comprising:
 a control system operably connected to the detector assembly. 
 
     
     
       12. The system of  claim 1  further comprising:
 a screen operably connected to the processor and configure to display the determined at least one separation distance between the first and second surfaces. 
 
     
     
       13. The system of  claim 1  further comprising:
 a control motor operably connected to the positioning structures. 
 
     
     
       14. The system of  claim 13  further comprising:
 a control system operably connected to the control motor. 
 
     
     
       15. The system of  claim 1  further comprising:
 a coupler located at the at least one excitation position on the first surface and configured to excite plasmon energy responsive to electromagnetic energy. 
 
     
     
       16. The system of  claim 15  wherein the coupler includes a prism. 
     
     
       17. The system of  claim 15  wherein the coupler includes a grating. 
     
     
       18. The system of  claim 15  wherein the coupler includes a topological defect. 
     
     
       19. An apparatus comprising:
 circuitry configured to provide plasmon energy to at least one excitation position on a first surface; 
 circuitry configured to receive a signal corresponding to detected plasmon energy at at least one measurement position on the first surface after the plasmon energy has propagated from the at least one excitation position to the at least one measurement position; 
 circuitry configured to determine an attenuation of plasmon energy along a plurality of different paths on the first surface and between the at least one excitation position and the at least one measurement position; and 
 circuitry configured to determine relative distances between the first surface and a second surface at a plurality of points on at least one of the surfaces based on the determined attenuation of plasmon energy along the plurality of paths. 
 
     
     
       20. The apparatus of  claim 19  wherein the circuitry configured to determine relative distances between the first surface and a second surface at a plurality of points is further configured to create an image of the second surface. 
     
     
       21. The apparatus of  claim 19  further comprising:
 circuitry configured to output the determined relative distances between the first surface and a second surface to a screen. 
 
     
     
       22. The apparatus of  claim 19  further comprising:
 circuitry configured to provide one or more signals to one or more microelectromechanical structures, wherein the one or more microelectromechanical structures are responsive to the one or more signals to adjust at least one of the first and second surfaces. 
 
     
     
       23. A method comprising:
 producing plasmon energy at at least one excitation position on a first surface; 
 detecting the plasmon energy at at least one measurement position on the first surface after the plasmon energy has propagated from the at least one excitation position to the at least one measurement position; 
 determining an attenuation of plasmon energy along a plurality of different paths on the first surface and between the at least one excitation position and the at least one measurement position; and 
 determining relative distances between the first surface and a second surface at a plurality of points on at least one of the surfaces based on the determined attenuation of plasmon energy along the plurality of paths.